| Cu In S2 quantum dots(CIS), as a new type of quantum dot, shows the advantages that many of the traditional quantum dot does not have. For example, it is environmental friendly because of its absence of toxic elements such as Cd, Te. Also, the fluorescence emission is easily to adjust to near infrared, which has advantages in bio-imaging and bio-analysis. Most of high quality Cu In S2 quantum dots are synthesized in organic phase, thus only with the hydrophilic modification, can the oil-soluble quantum dots been used for such application. Hydrophilic modification by amphiphilic polymer could protect the quantum dots surface ligands will not be damaged, and the sensitivity of quantum dots to the external environment will be kept. Quantum dots are easily functionalized. then be used for complex applications by compositing quantum dots and other nano materials. Based on this, the thesis is aimed to design two different methods to hydrophilic modifying oil-soluble CIS QDs. Under the foundation of that, assemble QDs on silicon spheres for composite material and quantum dots of dual color fluorescence probe can be obtained by functionalization of quantum dots. and try for the analysis and detection.The main contents are as follows:1. One-pot synthesized PAA-HDA with polyacrylic acid and hexa decanamine, and use this amphiphilic polymer for hydrophilic modification of oil-soluble CIS quantum dots, study result shows that each 100μL oil solution of CIS quantum dot solution using 3mg PAA-HDA hydrophilic modification is most appropriate. According to the characterization results, this method of hydrophilic modification of the CIS quantum dots maintains the excellent fluorescence properties with high intensity of 700 nm emission near infrared fluorescence, the hydrate particle size of 15 nm means it is well dispersed in water. Using the method of hydrophilic modification leaves the QDs rich surface carboxyl, easy functionalized for application;2. The oil soluble of CIS quantum dots was assembled to 56 nm thiolated silica spheres synthesized by inverse phase microemulsion, and CIS@Si O2 composite was prepared. Using PAA-HDA amphiphilic polymer on oil solution of CIS@Si O2 composite for hydrophilic modification, water solution of CIS@Si O2 nanoparticles as fluorescence probes was obtained. The probe of hydrated particle size is 60~80nm, has excellent optical properties, to near infrared emitting stable 700 nm. A certain concentration of Cu2+, Fe3+, Hg2+ and other metal ions can cause the fluorescence quenched. Studies have shown that 2 m M concentration range for the fluorescence probe to linear reflect the mercury ion concentration in 500 um to, the linear regression coefficient for 0.99214;3. Thiol beta cyclodextrin was used for simple and efficient to hydrophilic modify for oil soluble CIS quantum dots. Adsorption of organic dye R6 G by the special structure of b-CD to prepare for the water soluble double color fluorescence probe. The ratiometric probe has about 50 ~ 80 nm hydrated particle size, at 550 nm with a certain intensity of green fluorescence, at 700 nm with a strong red fluorescence and the probe under ultraviolet light with red fluorescence. The probe can be used to detect small molecules which containing benzene ring structure in it. The study found that with benzene sulfonic acid sodium concentration changes, the two-color fluorescence intensity ratio changes approximately linearly, the regression coefficient R=0.96903. The ratiometric probes can be simple prepared, have good fluorescence properties and the films contain thiol, easily were functionalize for a broad application prospects. |
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